This invention relates generally to an improved string detector for a coin-sensing device, and more particularly to an improved assembly for detecting the presence or absence of a string, and to an improved string detector that includes means operatively interconnecting a switch means conditioned to a first or second state by the presence or absence of a string, and a coin validation means conditioned from one state to a second state by a valid coin, for determining the handling of the coin depending upon the states of the switch means and coin validation means.
It is well known that persons will attempt to cheat a vending machine or the like controlled by a coin-accepting device by inserting a coin with a string attached. By manipulation of the coin with the string, such persons will attempt to control the coin in its passage through the coin-accepting device so that undeserved monetary credits will be given and vending of products from the vending machine will be realized without the appropriate amount of money being inserted into the coin-accepting device. The string also permits the coin for this unlawful purpose to be retrieved by the user.
There are many prior art devices that tend to discourage the use of a string attached to a coin for this objectionable, illegal purpose. For example, there are devices that include cutters that sever the string and preclude the manipulation of the coin. Other devices limit movement of a valid coin after one appropriate switch actuation for credit purposes incident to vending, and thereby preclude subsequent credit by the same coin. There are still other devices that grip and hold the string to preclude any movement of the string after the coin is inserted. This latter type of device is objectionable in that it usually requires servicing of the device to release and remove the string.